The present invention is directed to pitot tube covers, and in particular is directed to a pitot tube cover which is removed automatically by sufficient air speed.
Present-day aircraft carry one or more pivot tubes. Normally, pitot tubes have forward projecting openings that when exposed to air pressure in movement, send air pressure information to an airspeed indicator or other aircraft instrument. When the aircraft is on the ground, it is important that external materials such as moisture, dust, and insects not contaminate the pitot tube.
In order to prevent such contamination, the pitot tube is covered by a pitot tube cover when an aircraft is grounded. This cover must usually be removed prior to an aircraft""s takeoff.
Conventional pitot tube covers can be expensive and complicated. Furthermore, there have been recorded incidents of pitot tube covers not being removed prior to flight, thus contributing to dangerous situations. The background art has addressed this problem to some extent.
U.S. Pat. No. 3,106,374 to Olson et al. discloses an automatically releasable static discharge guard. This guard has a body made of plastic rubber neoprene. It includes a boar for receiving the outer end of a static discharge tube. The other end of the guard is provided with a frusto-conical section having an open end. In the event that the guard is left on the static discharge tube during flight, the air stream entering the opening causes the guard to be detached from the static discharge tube.
U.S. Pat. No. 5,026,001 to Wright et al. discloses a pitot static tube cover made out of a rigid material skeleton covered with a ceramic braid. A cross-bar with holes is provided so that the pitot static tube cover may be mounted or dismounted by pole from the ground.
U.S. Pat. No. 5,127,265 to Williamson et al. discloses a flame and heat-resistant cover for an airplane pitot tube. The cover includes a woven tube of fire-resistant fibers. The front of the tube is gathered and is sown with a fire-resistant non-abrasive thread. The cover is forced off of the tube when sufficient air speed is achieved to cause the cover to rotate off its position.
U.S. Pat. No. 2,786,353 discloses a pitot tube cover for selected placement over a pitot tube. The cover includes a shell having an enclosure and a funnel-shaped flange at the forward end of the shell. The cover is made of a plastic or metal, and is provided with a thin section or weakened ridges which extend along the entire length of the cover. In the event that the cover is left on the pitot tube, the air stream entering the flange causes the shell to break apart at the ridges and therefore fall off the pitot tube.
U.S. Pat. No. 2,532,316 discloses an automatically releasable cover for protecting a pitot tube. The releasable cover is made up of two L-shaped metal strips and fabricated of spring steel, which is stitched into the fabric. Two opposite latching studs or detents are also provided so that when the fabric is folded over the pitot tube, the spring steel metal strips are retained together. A deflector extends below the cover and cooperates therewith in a manner whereby the air pressure against the deflector causes the cover to pivot. This also causes the latching studs to detach from one another, thereby causing the cover to fall off the pitot tube.
U.S. Pat. No. 2,488,310 discloses an automatic shutter mechanism for a pitot tube. The mechanism includes a shutter attached to a shutter shaft, which extends through a clam bearing and bears the plunger spring. A wind pressure plane is attached to the shaft. In operation, air which is forced against the pressure plane forces the pressure plane along with the shutter shaft and shutter rearwardly against the spring, thereby uncovering the opening of the pitot tube.
U.S. Pat. No. 5,938,147 to DeGroff discloses a pitot tube cover arranged with a slot to encompass the pitot tube, and a wooden surface that is perpendicular to the direction of travel of the vehicle upon which the pitot tube is mounted. Once the vehicle reached a predetermined speed, sufficient force is applied against the wind surface, causing the cover to rotate about a pivot area, thereby freeing itself from the pitot tube and allowing the pitot tube to operate normally.
While some of the conventional art has provided pitot tube covers that automatically are removed from the pitot tube once a certain airspeed is achieved, the conventional designs are not suitable for all shapes and sizes of pitot tube. Certain configurations of pitot tube cannot be handled by the aforementioned examples of conventional art. As always, such cover must be light, simple and inexpensive so that its loss in air does not constitute an unreasonable expense. Further, the cover must be of a sufficiently light material that ejection of the cover does not cause air frame damage should the cover hit the plane.
Consequently, it is a primary object of the present invention to provide a pitot tube cover that automatically exposes the pitot tube opening when the aircraft is in flight.
It is a further object of the present invention to provide a pitot tube cover that uses the air pressure to separate the pitot tube cover form the pitot tube.
It is another object of the present invention to provide a pitot tube cover that prevents moisture, dust, insects, and other external contaminants from entering the pitot tube opening.
It is an additional object of the present invention to provide a pitot tube cover that can be easily mounted on the pitot tube.
It is still a further object of the present invention to provide a pitot tube cover that is easily cleaned.
It is yet another object of the present invention to provide a pitot tube cover cover that is lightweight so that it does not cause any damage when dropped from any aircraft at high altitudes.
It is again a further object of the present invention to provide a pitot tube cover with a simple, inexpensive design.
It is still an additional object of the present invention to provide a pitot tube cover capable of handling a wide variety of pitot tube shapes and sizes.
It is yet a further object of the present invention to provide a pitot tube cover that is adjustable so that separation air speeds can be selected.
These and other objects and goals of the present invention are achieved by a cover for a pitot tube mounted on an aircraft. The cover has a center split along the entire vertical axis and extends horizontally from the front to the rear of the cover in the center. It also has a molded cavity at the split for encompassing the pitot tube and also a tensioning strap to hold the cover onto the pitot tube. There is also a sloped wind surface on the front of the cover, channeling the wind into the split thereby separating the cover from the pitot tube and allowing the tube to be exposed.